Method for treating a flux coating

ABSTRACT

A method for providing a smooth coating of flux material uniformly distributed on a metal surface comprising directing a flame onto the flux-coated surface. The apparatus comprises a flame distributor adapted to contact the surface of the flux coating with a high-heat flame. The impingement of the flame on the flux surface causes an initial set in the flux surface which is smooth and evenly distributed.

United States Patent Peoples 451 Jan. 18, 1972 [54] METHOD FOR TREATING A FLUX CUATING [72] lnventorz Richard A. Peoples, Hamburg, NY. [73] Assignee: Bethlehem Steel Corporation [22] Filed: Nov. 29, 1968 [21 Appl. No; 780,062

[52] U.S.Cl ...117/46FA, 117/51, 117/64 R, ll7/115,117/119.6,117/127,118/47,117/46 FC [51] 11nt.Cl. ..C23c l3/02;,C23c 3/00 [58] Field ofSearch ..117/46,115,51,52,64 R, 117/127, 46 FA, 119.6; 118/47; 148/23, 26

[56] References Cited UNITED STATES PATENTS 857,886 Miller ..117/46 Roberts ..117/51 Mowry ..1 17/46 933,324 9/1909 1,582,668 4/1926 Dreifus ...117/46 2,007,221 7/1935 Smith ..1 17/51 2,813,044 ll/l957 Chester ..1 17/51 3,181,963 5/1965 Cook et al. ,.1 17/51 Priman Emminer-Alfred L. Leavitt Assistant Examiner- Edward G Whitby Anome v-Joseph J. OKeet'e [57] ABSTRACT A method for providing a smooth coating of flux material uniformly distributed on a metal surface comprising directing a flame onto the flux-coated surface. The apparatus comprises a flame distributor adapted to contact the surface of the flux coating with a high-heat flame. The impingement of the flame on the flux surface causes an initial set in the flux surface which is smooth and evenly distributed.

5 Claims, 2 Drawing Figures PATENTED JAN? 8 197 ZNVENTOR Richard A. Peep/es METHOD FOR TREATING A FLUX COATING BACKGROUND OF THE INVENTION The preparation of metal strip for metal-coating comprises applying a flux base to the substrate or basic metal strip. Heretofore this has been accomplished in the following manner. The metal strip or strandlike material is advanced through a bath of the fluxing material. Upon leaving the flux bath the strip is directed through a series of metering rolls and levelling brushes to smooth and meter the flux application, thence into a heating chamber where the open flames confined within the chamber walls thoroughly dry the flux on the metal strip. The strip is furtherdirected through another heating chamber which raises the temperature of the fluxed strip before it enters the bath of molten metal coating.

The wringer or metering rolls used to meter the flux tend to wear quickly due to the constant traveling of the sheet across the roll surfaces. When the metering rolls become worn the flux application is nonuniform resulting in coating problems. The levelling brushes which follow the metering rolls are used to smooth out or level the flux solution on the advancing strip. The action of the brush surface on the still liquid fluxed coating causes bubbles to form, creating an uneven flux coating when the flux coated strip emerges from the drying oven.

It is an object of this invention to provide a method of treating the flux coating on an advancing strandlike material to ensure a smooth and even flux surface.

It is a further object of the instant invention to provide improved apparatus for applying an even coating of flux on the surfaces of an advancing metal strip.

SUMMARY OF THE INVENTION The instant invention accomplishes these objects by impinging the surface of the flux coating with a high-heat flame to provide a quick set of the outer layer of flux coating and apparatus to implement this method. A quick set ensures against runback or dripping of the flux material and formation of bubbles or other unevenness of the coating. The flux-coated strip is then advanced through a conventional drying oven or heating chamber where the flux layer is completely dried prior to passing over guide rolls on its way to further processing for the final coating operation.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagrammatic elevational view of apparatus for coating a strandlike article; and

FIG. 2 is a view in perspective of a portion of the apparatus according to the instant invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT The invention will now be described in detail with particular reference to the drawings. FIG. 1 is a diagrammatic view of the apparatus including the instant invention for fluxing and coating metal strip. The strip 10 is seen advancing through a bath ll of aqueous flux solution guided therethrough by guide rolls 12. The strip 10 exits from the bath 11 and advances vertically upward through a series of metering rolls 13 and levelling brushes 14 which are mounted externally of the bath 11 and which distribute the flux coating substantially uniformly on the surfaces of the strip. Upon emerging from the series of metering rolls and levellingbrushes the advancing strip passes between a set of opposing high-heat direct-fired. flame burners 22 to be described later in more detail. Immediately thereafter the advancing flux-coated strip enters a drying chamber 16 containing open flame burners, not shown, which dry the flux coating on the strip or strandlike substrate. The strip 10 is then passed over guide rolls l7 and 18 thence into a second. heating chamber l9and finally into and through the bath 20 of the coating material.

Referring now to FIG. 2 which shows a perspectiveview of the burner unit 15 the strip is seen being impinged directly by a high-heat flame. The high-heat flames 21 are created by an air and gas mixture which is directed through spaced nozzles or openings in opposing flame distributors 22 which are mounted one on each side of the advancing strip 10 and are transversely coextensive therewith. The burner unit 15 which comprises the flame distributors 22 is seen mounted in close proximity to the exit of the strip 10 from the flux bath 11. This arrangement is necessary so that the layer of flux adhering to the strip surfaces is evenly distributed and quick set before dripping or runback can occur.

The intimate contact of the high-heat flame impinging on the flux surface turns the bubbles into steam effecting a flash evaporation, thereby smoothing said surface. Passage of the flux coated strip through drying chamber 16 immediately following the quick set provides a thorough drying of the flux coating on the substrate thus preventing damage to the now stable coating as it passes over the guide rolls l7 and 18 to further processing. The flames in the drying chamber 16 do not contact the strip merely supplying heat to the drying chamber 16. It is important that a high-heat flame be impinged on the liquid flux surface more or less directly. It is obvious however that the high-heat flame can perform its task equally well if placed at an angle to the strip surface if desired. The action of the high-heat flame impingement has a doctoring effect thus spreading the flux evenly as the bubbles are evaporated and this results in eliminating at least some of the metering rolls.

Although the description has referred to my novel treatment as applied to strip, it should be understood that any strandlike article such as wire is equally adapted to be so treated and is within the purview of the invention.

In the claims:

1. A method for treating a flux coating on a metal strandlike article in which said strandlike article is passed through an aqueous flux solution and thereafter through means external of the bath to distribute said flux evenly on said strandlike article, the improvement comprising:

a. flame-wiping the surface of said flux coating to smooth said coating, eliminate bubbles therefrom and completely dry said surface, and

b. passing said article to drying means to completely dry said flux coating.

2.-A method for treating a flux coating on metal strip in which said strip is passed through an aqueous flux solution and thereafter through means external of the bath to distribute said flux evenly on said strip, the improvement comprising:

a. flame-wiping the surface of said flux coating with a flame transversely coextensive with said strip to smooth said coating, eliminate bubbles therefrom and completely dry said surface, and

b. passing the strip through a drying oven to completely dry said flux coating.

3. A method for treating a flux coating on a metal strandlike article in which said strandlike article is passed through an aqueous flux solution and thereafter vertically upward through means external of the bath to distribute said flux evenly on said strandlike article, the improvement comprising:

a. flame-wiping the surface of said flux coating to smooth said coating, eliminate bubbles therefrom and completely dry said surface, and

b. passing said article to drying means to completely dry said flux coating.

4. A method for treating a flux coating on metal strip in whichsaid metal strip is passed through an aqueous flux solution and thereafter vertically upward through means external of the bath to distribute said flux evenly on said strip, the im provement comprising:

a. flame-wiping the surface of said flux coating with a flame transversely coextensive with said strip to smooth said coating, eliminate bubbles therefrom and completely dry said surface, and

b. passing said strip through a drying oven to completely dry said flux coating.

5. A method for producing a smooth, even flux coating on a strandlike article including the steps of:

a. passing said strandlike article through an aqueous flux said coating, eliminate bubbles therefrom and completely solution, dry said surface, and

b. distributing said flux coating evenly on the surface of said Passing said article through a drying Oven to completely strandlike article after leaving said bath, y Said flux coatingc. flame-wiping the surface of said flux coating to smooth 5 

2. A method for treating a flux coating on metal strip in which said strip is passed through an aqueous flux solution and thereafter through means external of the bath to distribute said flux evenly on said strip, the improvement comprising: a. flame-wiping the surface of said flux coating with a flame transversely coextensive with said strip to smooth said coating, eliminate bubbles therefrom and completely dry said surface, and b. passing the strip through a drying oven to completely dry said flux coating.
 3. A method for treating a flux coating on a metal strandlike article in which said strandlike article is passed through an aqueous flux solution and thereafter vertically upward through means external of the bath to distribute said flux evenly on Said strandlike article, the improvement comprising: a. flame-wiping the surface of said flux coating to smooth said coating, eliminate bubbles therefrom and completely dry said surface, and b. passing said article to drying means to completely dry said flux coating.
 4. A method for treating a flux coating on metal strip in which said metal strip is passed through an aqueous flux solution and thereafter vertically upward through means external of the bath to distribute said flux evenly on said strip, the improvement comprising: a. flame-wiping the surface of said flux coating with a flame transversely coextensive with said strip to smooth said coating, eliminate bubbles therefrom and completely dry said surface, and b. passing said strip through a drying oven to completely dry said flux coating.
 5. A method for producing a smooth, even flux coating on a strandlike article including the steps of: a. passing said strandlike article through an aqueous flux solution, b. distributing said flux coating evenly on the surface of said strandlike article after leaving said bath, c. flame-wiping the surface of said flux coating to smooth said coating, eliminate bubbles therefrom and completely dry said surface, and d. passing said article through a drying oven to completely dry said flux coating. 